1. Field of the Invention
The invention relates to the field of portable hand-held analytical devices for analysis of medically significant components of samples, in particular biological fluids, comprising analytical measuring units, which receive replaceable drum cartridges, which can contain analytical consumables, in particular test strips.
2. Description of Related Art
Support-bound rapid tests have become established for chemical and biochemical analysis of solid and liquid sample materials in specialized laboratories and also, in particular, for the use outside of stationary laboratories. Based on a special-developed dry chemistry, these support-bound rapid tests can be performed easily and without complications even by untrained individuals despite the often complex reactions involving sensitive reagents.
A known example of support-bound rapid tests are test elements for the determination of the blood glucose level of diabetics. Diagnostic test elements provided in the form of strips are also called test strips. Known embodiments thereof include single- or multiple-field test strips for urine analysis and various indicator papers. Since support-bound tests also exist in a variety of shapes other than test strips, they are more generally denoted as “analytical consumables”.
Such analytical consumables are packaged in a storage container in order to protect them from detrimental environmental influences, e.g. light, moisture or mechanical impact, and store them under sterile conditions. Aside from test strips, analytical consumables include for example lancets and sampling elements.
Since analytical consumables of this type have been described comprehensively in the prior art and a variety of embodiments thereof are known to experts in the field, no detailed description shall be provided herein. The analytical consumables are stored in a drum cartridge for example of the type described in European Patent Application No. 1 022 565 A2.
Portable hand-held analytical devices for analysis of a biological fluid, such as for example devices for the determination of blood glucose levels, are commonly used by individuals whose manual dexterity is impaired due to illness or age. For this reason, it is important for such analytical devices to be as easy as possible to operate with operating errors being largely excluded. A critical point in this context has proven to be the insertion or replacement of a drum cartridge in the analytical device. On the one hand, it is necessary to ensure exact positioning of the drum cartridge to ensure that the analytical consumables contained in the drum cartridge can reliably interact with the analytical sensor of the analytical device; on the other hand, the replacement of a drum cartridge must require no more than a low level of manual dexterity from the user of the analytical device.
Commonly marketed hand-held analytical devices are of a structure as described for example in U.S. Pat. No. 5,632,410 and U.S. Pat. No. 5,510,266. In an analytical device of this type, the drum cartridge is borne on an axis which extends through the entire length of the drum cartridge. This arrangement provides for sufficient positioning of the drum cartridge. However, it is also associated with the disadvantage of the drum cartridge being difficult to replace, since the axis must be pushed through a central bore hole of the drum cartridge which requires a considerable level of manual dexterity.
Moreover, Accu-Check® Compact™ blood glucose monitoring systems (Reference Manual. Publ. No. 03307689001 (08/02), Roche Diagnostics, Mannheim, 2002) are known from prior public use. These monitoring devices comprise a loading opening for receiving a drum cartridge which opening can be closed by a lid. An axis is situated in the loading opening onto which the drum cartridge can be slipped. The lid is closed by a swiveling motion and, in its closed state, presses onto the front side of the drum cartridge fixing the drum cartridge in its working position. However, for some measurements, a more precise axial positioning is desirable. Also, the drum cartridge can drop from the device upon opening of the loading opening causing further inconvenience.